建立了一种通过电喷雾电离-离子迁移谱(ESI-IMS)结合金属离子辅助技术快速同时测定多菌灵和噻菌灵残留的方法,并在不同水果基质中进行了验证。执行金属离子辅助策略而不是繁琐的预分离程序以克服IMS的低分辨率的限制。四种过渡金属阳离子,Co(II),Ni(II),Cu(II),和锌(II),进行了筛选,并研究了它们与多菌灵和噻菌灵的相互作用。优化了注射流速和金属离子浓度。Cu(II)辅助方法有助于实现分离良好的峰,峰-峰分辨率为3.61。该方法用于同时检测苹果中的多菌灵和噻菌灵。梨,香蕉,还有芒果.多菌灵和噻菌灵的检出限(LOD)分别为0.03mgkg-1和0.13mgkg-1,分别,加标回收率为61.5-122.0%和83.5-119.8%,分别,RSD低于13.9%。这些令人满意的评估参数表明,该方法能够对多种农药残留进行定量分析。此外,通过分子静电势分析和基于密度泛函理论(DFT)的结合能计算,从理论上证明了使用金属离子辅助ESI-IMS同时检测的可行性。实验和理论结果都揭示了金属离子辅助策略在提高ESI-IMS分辨率方面的有效性。
A method for the rapid and simultaneous determination of carbendazim and thiabendazole residues by electrospray ionization-ion mobility spectrometry (ESI-IMS) combined with a metal ion-assisted technique was developed and validated in different fruit matrices. The metal ion assisted strategy was performed instead of tedious pre-separation procedures to overcome the limitation of low resolution of IMS. Four transition metal cations, Co(II), Ni(II), Cu(II), and Zn(II), were screened and their interactions with carbendazim and thiabendazole were investigated. The injection flow rate and metal ion concentration were optimized. The Cu(II) assisted approach helped to achieve well-separated peaks with a peak-to-peak resolution of 3.61. This method was then applied to detect carbendazim and thiabendazole simultaneously in apples, pears, bananas, and mangoes. The limit of detection (LOD) were 0.03 mg kg-1 and 0.13 mg kg-1 for carbendazim and thiabendazole, respectively, while spiked recoveries were 61.5-122.0% and 83.5-119.8%, respectively, with RSDs less than 13.9%. These satisfactory evaluation parameters indicated that the approach was capable of performing quantitative analysis of multi-pesticide residues. In addition, the feasibility of using metal ion assisted-ESI-IMS for the simultaneous detection also was theoretically demonstrated through molecular electrostatic potential analysis and binding energy calculation based on density functional theory (DFT). Both experimental and theoretical results revealed the effectiveness of the metal ion assisted strategy in improving the resolution of ESI-IMS.